This invention relates to a coupling device for coupling rotating shafts of mechanical parts of locating them coaxially and engaging them in the direction of rotation thereof.
As for coupling devices of the kind specified, there have so far been employed elastic rubber couplings and cross joints etc. which are adapted to accommodate dimensional errors or deviations in the manufacture of mechanical parts.
However, in case of connecting a small precision electronic part, for example, a potentiometer with a rotating shaft of manual lever or foot pedal, the above-mentioned arrangement is disadvantageous in that it is uneconomical in respects of the space and cost thereof. Further, in case of the potentiometer, because it serves to transmit the angle of rotation instead of the number of rotations, its efficiency will drop even with a small play. Where the arrangement is simplified using slits or yokes in place of the above-mentioned prior art example, deviations in the angle of rotation will increase even with a small play of the parts and so its efficiency will become lower as mentioned above. If the play of mechanical parts is reduced to prevent such a trouble, the difficulties encountered in the manufacture and assembly of them can be eliminated; however, there is a disadvantage in that when a play occurs in the rotating shaft on the driving side like a pedal shaft etc. due to a change with the lapse of time, the potentiometer may be damaged.